Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules), Legion of the Bouncy Castle Inc. BCPKIX-FIPS bcpkix on All (pkix modules). This vulnerability is associated with program files JcaContentVerifierProviderBuilder.Java. This issue affects BC-JAVA: from 1.67 before 1.84; BCPKIX-FIPS: from 2.0.6 before 2.0.11, from 2.1.7 before 2.1.11.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Bouncycastle
  • Bc-java

No data.

No data.

References
Link Providers
https://github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057 cve-icon cve-icon
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588 cve-icon cve-icon
History

Tue, 21 Apr 2026 16:00:00 +0000

Type Values Removed Values Added
Description Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules).This issue affects BC-JAVA: from 1.67 before 1.84. Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules), Legion of the Bouncy Castle Inc. BCPKIX-FIPS bcpkix on All (pkix modules). This vulnerability is associated with program files JcaContentVerifierProviderBuilder.Java. This issue affects BC-JAVA: from 1.67 before 1.84; BCPKIX-FIPS: from 2.0.6 before 2.0.11, from 2.1.7 before 2.1.11.
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/U:Green'}

 cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber'}

Tue, 21 Apr 2026 15:30:00 +0000

Type Values Removed Values Added
Description : Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules). PKIX draft CompositeVerifier accepts empty signature sequence as valid. This issue affects BC-JAVA: from 1.49 before 1.84. Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules).This issue affects BC-JAVA: from 1.67 before 1.84.
References

Wed, 15 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

 ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 15 Apr 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics cvssV4_0

{'score': 10, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'}

 cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/U:Green'}

Wed, 15 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Bouncycastle
Bouncycastle bc-java
Vendors & Products Bouncycastle
Bouncycastle bc-java

Wed, 15 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 15 Apr 2026 09:30:00 +0000

Type Values Removed Values Added
Description : Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules). PKIX draft CompositeVerifier accepts empty signature sequence as valid. This issue affects BC-JAVA: from 1.49 before 1.84.
Title PKIX draft CompositeVerifier accepts empty signature sequence as valid.
Weaknesses CWE-327
References
Metrics cvssV4_0

{'score': 10, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: bcorg

Published: 2026-04-15T09:06:15.617Z

Updated: 2026-04-21T15:43:55.191Z

Reserved: 2026-04-04T23:50:59.336Z

Link: CVE-2026-5588

cve-icon Vulnrichment

Updated: 2026-04-15T13:11:21.652Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-15T10:16:49.597

Modified: 2026-04-21T16:16:20.540

Link: CVE-2026-5588

cve-icon Redhat

No data.